34 BYZANTINE CHURCHES CHAP, i
There is nothing in either the planning or the construction of S. Sophia which cannot be derived from the buildings of the Roman Imperial periodj with the exception of the pendentive, a feature which had to be evolved before the dome could be used with freedom on any building plan on a square. The great brick-concrete vaulted construction is that of the Roman bathss and with this is united a system of decoration founded on the classic models^ but showing no trace of the Greek beam tradition which had ruled in Rome.
S. Sophia then may be regarded as the culminating point of one great Roman-Byzantine school^ of which the art of classic Rome shows the rise^ and the later Byzantine art the decline. This view is in accord with history3 for Constantinople was New Rome3 and here, if anywhere, we should expect to find preserved the traditions of Old Rome.
The division of Western Mediaeval Architecture into the two schools of Romanesque and Gothic presents a parallel case. It is now realised that no logical separation can be made between the two so-called styles. Similarly we may continue to speak of the Classic Roman style and of the Byzantine style, although the two really belong to one great era in the history of art